It is increasingly important to the fastener industry, and especially as it serves the automobile industry, to apply plural and diverse coatings to various portions of a single part. For example, threaded areas may need to be coated with a good bearing material or adhesive material while adjacent areas may require painting or plating for maximum corrosion resistance and the coating materials could interfere with the bonding of the next adjacent surface. This is especially true where the internal surfaces are coated with a material which would act as a resist to subsequent treatment of the exterior of the portion of the resist-reached area and adjacent to the treated area. Present known procedures for fasteners are slow, manual and generally unsatisfactory.